Renal allograft recipients suffer from a high frequency of cytomegalovirus infections. When the transplant recipient is seropositive these infections appear to be secondary to reactivation. When the transplant recipient is seronegative, donor kidneys from seropositive individuals may transmit primary infection. Primary transmission with CMV after transplantation is associated with a high rate of symptomatic infection and there is a possible association with kidney rejection. Bone marrow transplant recipients are also susceptible to CMV infection, transmitted either by donor marrow or by reactivation of latent infection. A live CMV vaccine has been developed and tested successfully in normal volunteers. This project, which explores the utility of vaccination in transplant patients, would consist of four parts: 1) An open trial in a limited number of renal graft recipients to verify safety. 2) A controlled trial in renal graft recipients to determine if vaccination would prevent primary CMV infection and disease. 3) Immunization of normal volunteers for the purpose of producing CMV antibody. 4) Prophylactic administration of CMV antibody-containing plasma or gamma globulin to recipients of bone marrow transplants.